MR DAMPER GENERATING RESPONSE-DEPENDENT FRICTIONAL FORCE FOR CONTROLLING BUILDING STRUCTURES EXCITED BY SEISMIC LOAD

摘要

In this study, a response-dependent MR damper of which frictional force is determined according to the assumed shape function composed of displacement and velocity of the damper piston itself, is designed and its performance is compared to the passive one and semi-active one using linear quadratic regulator. Numerical analysis results from SDOF system indicate that passive MR damper designed to have appropriate frictional force of which magnitude is less than about 30percent of the base shear force, provides the smallest displacement response spectrum over all structural periods and response-dependent MR damper show better control performance in reducing absolute acceleration spectrum with increasing frictional force for the long period structure. Also, seismic analysis of a three story structure with the MR damper shows that well designed response-dependent MR damper provides performance equivalent to or better than the semi-active MR damper operated by LQR controller in spite of using only the structural response transferred to the damper.